Transcript RISK MANAGEMENT - Indonesian Computer University

Magister Sistem Infomasi
Universitas Komputer Indonesia
SOURCE:
LARSON, E.W., GRAY C.F., 2011, 5TH ED.;
PINTO, J.K. 2010, 2ND. ED.
PROJECT NETWORK PLANNING
Program/Project Evaluation and Review Technique (PERT)
Critical Path Method (CPM) – Project Crashing
Precedence Diagram Method (PDM)
PERT
(PROGRAM EVALUATION & REVIEW TECNIQUE)
• In 1958 the Special Office of the Navy and the
Booze Allen, and Hamilton consulting firm
developed PERT to schedule the more than
3,300 contractors of the Polaris submarine
project and to cover uncertainty of activity
time estimates.
• PERT is almost identical to the critical path
method (CPM) except it assumes each activity
duration has a range that follows a statistical
distribution.
Activity and Project Frequency Distributions
Activity
a
m
Project
b
TE
Weighted Average Activity (te)
a + 4m + b
te
te
a
b
m
= ------------6
= weighted average activity time
= optimistic activity time (1 chance in 100
compliting activity under normal conditions)
= pesimistic activity time
= most likely activity time
Activity Standard Deviation
b-a
σte =
-----
6
σ = √ ∑ (σte )²
TE
Probability of Completing the Project in Time
Z
=
Ts – TE
--------------
√ ∑ (σte )²
TE = Critical path duration
TS = Schedule project duration
Z = probability (of meeting scheduled duration)
found in statistical
Z Values and Probabilities
Z Value
Probability
Z Value
Probability
-3.0
.001
+0.0
.500
-2.8
.003
+0.2
.579
-2.6
.005
+0.4
.655
-2.4
.008
+0.6
.726
-2.2
.014
+0.8
.788
-2.0
.023
+1.0
.841
-1.8
.036
+1.2
.885
-1.6
.055
+1.4
.919
-1.4
.081
+1.6
.945
-1.2
.115
+1.8
.964
-1.0
.159
+2.0
.977
-0.8
.212
+2.2
.986
-0.6
.274
+2.4
.992
-0.4
.345
+2.6
.995
-0.2
.421
+2.8
.997
Example
Activity
a
m
b
1-2
17
29
47
2-3
6
12
24
2-4
16
19
28
3-5
13
16
19
4-5
2
5
14
5-6
2
5
8
1. Compute the expected time for each activity
2. Compute the variance for each activity
3. Compute the expected project duration
4. What is the probability of completing the project by day 67?
Within 60 days?
ANSWER
Actvity
a
m
b
te
((b-a)/6))^2
1-2
2-3
2-4
3-5
4-5
5-6
17
6
16
13
2
2
29
12
19
16
5
5
47
24
28
19
14
8
30
13
20
16
6
5
25
9
4
1
4
1
Answer – Hypothetical Network
0
A
30
Legend
ES
ID
EF
SL Description
LS Dur
LF
B
D
13
16
C
E
20
6
F
5
Answer - Probability
Z
=
Ts – TE
--------------
√ ∑ (σte )²
67 – 64
Z
=
-----------------
√ 25 + 9 + 1 + 1
P
=
0.69
+3
= -------- = + 0.5
√ 36
Exercise 1
 Given the project information below, what is the
probability of completing the National Holiday Toy
project in 93 time units?
Act. Description
ID
Predecess
or
Optm.(a)
Most
Likely (m)
Pess (b)
1
Design package
None
6
12
24
2
Design product
1
16
19
28
3
Build package
1
4
7
10
4
Secure patent
2
21
30
39
5
Build product
2
17
29
47
6
Paint
3,4,5
4
7
10
7
Test market
6
13
16
19
Exercise -2
 Using the following information, create an AON network activity diagram.
Calculate each activity TE, total duration & Critical Path
Activity
Preceeding
Activities
Best
Likely
Worst
A
-
12
15
25
B
A
4
6
11
C
-
12
12
30
D
B,C
8
15
20
E
A
7
12
15
F
E
9
9
42
G
D,E
13
17
19
H
F
5
10
15
I
G
11
13
20
J
G,H
2
3
6
K
J,I
8
12
22
Exercise -3
 The Global Tea and Organic Juice companies have merged. The following
information has been collected for the “Consolidation Project”.
Act Description
Predecessor a opt m ml
b pess
1
Codify accounts
None
16
19
28
2
File articles of unification
None
30
30
30
3
Unify price and credit policy
None
60
72
90
4
Unify personnel policies
None
18
27
30
5
Unify data processing
1
17
29
47
6
Train accounting staf
1
4
7
10
7
Pilot run data processing
5
12
15
18
8
Calculate P&L and balance sheet
6,7
6
12
24
9
Transfer real property
2
18
27
30
10
Train salesforce
3
20
35
50
11
Negotiate with unions
4
40
55
100
12
Determine capital needs
8
11
20
29
13
Explain personnel policies
11
14
23
26
14
Secure line of credit
9,12
13
16
19
15
End
10,12,14
0
0
0
Exercise 3 - Question
 1. Compute the expected time for each activity.
 2. Compute the variance for ecah activity
 3. Compute the expected project duration.
 4. What is the probability of completing the project by day 112? Within 116 days?
 5. What is the probability of completing “Negotiate with Unions” by day 90?
Solve exercise 1 Using WIN QS
 File – New Problem
Input the data
Solve and Analyse – Solve Critical Path
Result – Gant Chart
Results – Perform Probability Analysis
Result – Perform Simulation
. Use system clock – edit Number of simulated observation –
Show Analysis